The marginal costs are pretty small. It could easily be handled by a site with an emphasis on simplicity like Craigslist.

Personally, I would prefer a non-profit. I can't stand a private company like Facebook being the primary gateway to my social life. I would like to see multiple companies involved, but it would be a lot more difficult to get the network benefits of Facebook with multiple sites.

A couple of years ago when FB first started causing privacy concerns, I sketched out a model for a freemium social networking site with user privacy as the top selling point. After deciding it was too early for the target market to consist of anything but Slashdot posters, I forgot about it.

Is it time to think about it again, or is it just Slashdot and HN posters this time?